1. Field of the Invention
This invention relates to the production of aminopolyols and polyaminopolyols, and particularly relates to methods of making aminopolyols from corn syrups by continuous reductive amination in which the degree of amination may by increased by reducing the mol ratio of ammonia to sugar.
2. Prior Art
Previously, aminopolyols or polyaminopolyols have been made using homogeneous catalysts. These methods required extensive filtering and catalyst recovery procedures. Further, many of the feedstocks used to make aminopolyols are quite expensive. It is therefore an object of this invention to provide a means for making aminopolyols using an inexpensive feedstock, such as corn syrups, and a heterogeneous catalyst such as a hydrogenation-dehydrogenation nickel catalyst.
A number of other researchers have reductively aminated glucose and other sugars. For example, J. W. Long and G. N. Bollenback in Methods of Carbohydrate Chemistry (R. L. Whistler and M. L. Wolfram, ed., Academic Press, N.Y.) Vol. 2, pp. 79-83 (1963) describe how D-glucose in a methanol solution reacted with ammonia over a nickel catalyst to give up water will produce 1-amino-1-deoxy-D-glucitol. A mixture of piperazines, mixtures of amino-alcohols, ethylenediamine, and water are produced over a nickel catalyst by reacting sucrose, cornstarch, Bagasse pith or glucose with NH.sub.3, MeNH.sub.2, MeCH.sub.2 NH.sub.2, or EtNH.sub.2 along with water and hydrogen as described in British Pat. No. 844,448. U.S. Pat. No. 4,021,539 discloses how monosaccharides or their corresponding uronic acids may be reacted with secondary or tertiary amines over palladium, copper-chromium, and nickel hydrogenation catalysts to produce N-polyhydroxyalkyl-amines which are useful in skin-treating cosmetic compositions.
The reaction of aldehydo or keto sugars with primary or secondary amines and hydrogen over palladium carbon catalysts to produce secondary or tertiary amino sugars is described in Tronchet, J. M. J; B. Baehler, H. B. Zomwald, Helv. Chim. Acta. 1977 60(6), 1932-34. The use of sodium bisulfite to inhibit the browning reaction of glucose and ammonia to make imidazoles has been disclosed in M. Komoto, S. Fujii and H. Tsuchida, Hyogo Noka Daigaku Kenkyu Hokuku, Nogei-Kagaku Hen 5, 124-8 (1962).